Biology DSM 54

what is true of the number of species alive on Earth today?

though scientists do not know the exact number of species, they do know what the lower limit (the minimal number) of species is

what will be the effect of climate change on global species diversity

overall, biodiversity will drop

what is the statement about human impact on earth

newly threatened species are at risk from deforestation and other forms of habitat destruction

what is a characteristic of habitat fragmentation?

species that prefer habitat edges do better than species that prefer habitat interiors

which of the following are liking mechanism for biodiversity increasing productivity?

certain species facilitate the growth of other species, more species means more niches for other species and greater productivity, resource use is more efficient

what is the effect of biodiversity on ecosystem productivity?

increased biodiversity increases productivity

which is the statement regarding mordern extinction rates?

they are 100 to 1,000 times greater than the background rate recorded in the fossil record

what is an exotic species

a nonnative species that is introduced into a new area

which of the following statements conservation hot spots?

they contain high numbers of endemic species per unit area

following threats to biodiversity

overexploitation, habitat loss and destruction, and pollution

researchers have been studying rare population of 87 voles in an isolated area. Ten voles from a larger population were added to this isolated population. Besides having 10 additional animals, what benefits are there to importing individuals

additional animals from a distant population will likely bring genetic diversity and reduce inbreeding depression

human are causing species extinction. Which taxonomic group has the highest percentage of threatened species?

amphibians

what is the name of the resource that uses the most water

beef

the species-area curve shows that

smaller areas have fewer species

what are the criteria for a biodiversity hot spot?

it contains at least 1500 endemic vascular plant species, it has lost at least 70% of its primary vegetation

where is the highest species richness on earth

around the equator in South America

what is the main reason conservationist are calling for immediate and open expensive action on behalf of endangered species and habitats?

biodiversity is beneficial to humans

in what way can introduced species have deleterious effects on biological communities

introduced species prey on native species, introduced species compete with native species for space or breeding and nesting habitat, introduced species compete with native species for food or light, and introduced species displace native species

DNA bar coding is used to

quickly identify species according to variation in one gene

to better comprehend the magnitude of current extinctions, it is necessary to …

identify more of the yet-unknown species of organisms on earth

the species-area relationship can estimate the rate of extinction based on projections of…

habitat destruction

researchers set out to catalog all the angiosperms present in a state park. This is an example of

a taxon-specific survey

what is an endangered species?

a species in danger of going extinct

which process result directly in habitat destruction?

damming rivers

where does biodiversity tend to be higher

in areas with greater geographic variation